双能CT对AIS血管内治疗后早期颅内出血的诊断价值

The differential diagnostic value of dual-energy CT for early intracranial hemorrhage and contrast agent extravasation after intravascular treatment of acute ischemic stroke

目的:评价双能CT(DECT)对急性缺血性脑卒中(AIS)患者血管内治疗后早期颅内出血(ICH)和对比剂外渗的鉴别诊断价值。方法:2017年11月-2019年2月对在本院接受血管内治疗的AIS患者在术后2h内行头颅DECT扫描(80kVp和Sn150kVp)得到的混合能量图像,经后处理获得虚拟平扫图(VNC)及碘覆盖图(IOM),以术后24~48h的常规CT(44例)或MR磁敏感加权血管成像(SWAN)(5例)的诊断结果作为参照标准(常规CT显示梗死区出现高密度影或SWAN图像显示低信号影即为出血),评价DECT图像(混合图像+VNC+IOM)对AIS患者血管内治疗后ICH的早期诊断效能。结果:符合纳入条件的49例AIS患者中15例DECT诊断为颅内出血合并对比剂外渗,全部经随访图像证实;34例诊断为对比剂外渗,随访证实30例,余4例随访图像提示出血性转化。DECT诊断早期ICH的敏感度、特异度及符合率分别为78.95%(15/19)、100%(45/45)和93.75%(60/64),阳性和阴性预测值分别为100%(15/15)和91.84%(45/49)。结论:双能CT可诊断AIS患者经血管内治疗后早期ICH并指导临床治疗。

Objective:The purpose of this study was to evaluate the value of dual energy CT(DECT)in the differential diagnosis of intracranial hemorrhage(ICH)and contrast agent extravasation after intravascular treatment of acute ischemic stroke(AIS).Methods:Forty-nine AIS patients who received endovascular treatment in our hospital from November 2017 to February 2019 were selected and analyzed retrospectively.Mixed energy images were obtained by immediate intracranial DECT scan(80kVp and Sn150kVp)within 2h after surgery,and virtual non-contrast(VNC)and iodine overlay map(IOM)were obtained after postprocessing.Taking the conventional CT(n=44)or MR susceptibility weighted angiography(SWAN)images(n=5)within 24~48h after operation as the reference standard(hemorrhage was defined as high-density on conventional CT images or low-signal region on SWAN images in the infarction area),the diagnostic efficacy of DECT images(fusion images+VNC+IOM)was evaluated.Results:Among the 49 AIS patients,15 were diagnosed as intracranial hemorrhage complicated with contrast medium extravasation by DECT,all were confirmed by follow-up scan.34 were diagnosed as contrast medium extravasation,30 of them were confirmed by follow-ups,the other 4 cases were identified as hemorrhagic transformation.The sensitivity,specificity,accuracy,positive and negative predictive value of DECT in early diagnosis of intracranial hemorrhage was 78.95%(15/19),100%(45/45),93.75%(60/64),100%(15/15)and 91.84%(45/49),respectively.Conclusion:Early intracranial hemorrhage after vascular treatment in AIS patients can be diagnosed by dual-energy CT scan,which can be used as a guidance for clinical treatment.